Adjustable pneumatic scale



Dec. 28 1926.

1,612,743 s. QulsLlNG ADJUS TABLE PNEUMATI C S CALE Filed May 2, 1924 gig. 3.

Miu-laf.

WITNESS:

ATTORNEY lating' the size ot this Patented Dec. 28, 1926.

SVERRE QUISLING, OF

PATENT OFFICE.

PHILADELYHIA, PENNSYLVANIA.

ADJUSTABLE PNEUMATIC SCALE.

`Application filed May 2, 1924. Serial No. 710.652.

This invention coniprehends the provision ot a scale or device for the accurate deternnnation ot weights by means ot a pneumatic spring deviceY a l 'ustable for all env1ronmental conditions ot ten'iperature and atmospheric pressure. The adjutable pneumatic scale is based on the principle ot Boyles law 'tor gasesto quote; The volume ot a varies inversely as the pressure upon it: and 'for the same temperature the density ot a gas is directly proportional to the pres?,- sure acting upon it. Thus` by varying the d ensity of a gas in a closed chamber by the pull ot weights transniitted to a piston regni chan'ibcr. there will be a change ot 'volume ot' said gas and chainber, which is measured and is directly pro portional to the respective weight applied. lly use ot a standard weight and varying the amount ot gas in the chamber, the device may be made accurate and calibrated for each condition ot barometric pressure and temperature.

More specifically, the invention includes a gas chamber with means for admit-ting desired quantities ot gas and means for variation ot' the size ot' said chamber by a second part or piston fitting into the chamber like a piston, and means for measuring volumetric charges ot gas being acted upon.

A further object ot' the invention is to provide a-n instrument as specitied, which can, in addition to being used to measure weights, be used for measuring barometric pressure on the principle that the volume of the gas varies inversely as the pressure acting upon it, and thus by noting the variation of the volume of the gas in the chamber of the device, the size of Which chamber is varied by the movable piston to which a constant 'force is applied, acting to increase the gas volume against the atmospheric pressure. ln such use, either the piston may be graduated to show various volumes corresponding to various barometric pressures, or any suitable contrivance may be associated with the device for indicating barometric pressures.

Other objects of the invention are to provide a pneumatic adj ustable scale which can be accurately calibrated for any baroinetric pressure and temperature, can be made ot' any suitable material, one which is simple in construction and accurate in the performingot' its functions.

Figure l is a side elevation o'l the iinproved scale.

Figure 2 is a vertical section through the scale.

Figure is a horizontal section through the scale taken on the line 3-3 otf Figure l.

Figure l is a vertical section through the invention, showing` it used as a barometer.

Referring more particularly to the dra\v ings, the improved s lale comprises a cylindrical bony l which is made ot any suitable material and has its onter surface screwthreaded at its ends.y as clearly shown in Figure Q et the dra\\'ings. A cap 2 is threaded upon one end oi the body l and a gaslct lil in used to provide a tluid-tiht joint between the cylinder or body and the cap Q. llie cap l is provided with a [luid inlet opening' L1- which enters the interior ot the body l inwardly ot the piston 5, that is, in the chamber G. A stop cock or valve 7 of any approved construction is carried by the cap for controlling the inlet of gas or air into or its outlet from the chamber 6.

The piston 5 lits tightly, preferably by an air tight or fluid-tight engagement With the inner surface of the cylindrical body 1, so as to prevent the escape ot' gas from the chamber 6 about the piston. It it is desired and necessary, an oil seal between the piston 5 and inner surface of the cylinder l may be used. The piston 5 has the hook S attached thereto at its lower end. The piston 5 is graduated or calibrated, as shown at 10, to indicate any known or given units ot' Weight directly proportional to the volume ot' gas in the chamber 6. A ring l1 is adjustably mounted on the lower threaded end of the cylinder 1 and it is adjusted to zero of the scale graduations on the piston, after the scale is adjusted barometrically by changing the amount of gas in the chamber (3 to obtain the principal or correct tension, as can be determined by use ot a constant Weight and the scale readinof.

From the 'foregoing description, taken in connection with the accompanying drawing, it will be apparent that a pneumatic scale has been provided which Will permit accurate positive Weighing of various articles,

irrespective of the environmental conditions surrounding the scale, in that by operation of the valve 7, the pressure in the chainber (3 inay be varied to give proper results at any bai'oinetric pressure or temperature.

Using the invention,` as shown in Figure t of the drawings, the device is employed as a barometer, and in such construction, the piston 5a has a weight 20 of any desired constant weight connected thereto in any suitable manner, such as by means of the rod 2l. The weight 2O pulling on the piston 5a against the force of the atmosphere will, in conjunction with the barometer calibrations 10"l show the barou'ietric readings. in the i'nodiied forni of the invention, the piston 5*"L is shown graduated, as at l0, as is also the piston 5, shown graduated at l0. ll'owever, it .is to be understood, that a suitable scale having the `graduatiions of either the weight or the baroinetric pressure, may be used in lieu of graduating `the n'iovabie inst-on, Yand that an indicating arin or lever niay be associated with the movable piston and scale to permit the readings.

The modified forni of the instrument includes besides the piston 5a and the Weight 20, the body la in which the piston 5EL is movable, and with the inner surface of which the piston has a i'iuid-tight engagement. The volume of gas in the chamber 6a inay be varied, by operation of the valve 7a which controls the passage of air or gas into the chan'iber 6a through the passage-Way ta in the cap 2a.

lvhilein the drawings and the foregoing description the bodies 1 have been referred to as cylindrical, it is to be understood that they n'ray be of any desired shape or conliguration found practical, without departing from the spirit of this invention.

lt is, of course, to be understood, that the invention may be constructed in various other manners and the parts associated in different relations, and therefore, l do not desire to be iiinited in any manner except as set forth in the claim hereunto appended.

Ihat l claim is:

En a device of the character described, the combination of a cylinder having a closure cap secured to the upper end thereof, a tubuiar piston disposed in said cylinder Vto foi-in a variable fluid-tight chamber in said cylinder between said closure cap and piston, and having a graduated scale expresslng units of weight prov'ded on the outer peripherv thereof adjacent its lower end, a suction release opening vertically disposed in said closure cap, valve stein disposed in said closure cap at right angles to said release opening, an aperture in said valve stein for registration with said release opening, and a suspension hoolr depending from the lower end of said piston with its parallel and laterally extending ends disposed within and pivoted to the skirt thereof for attaching a weight to said hook to determine the weight thereof substantially as described.

ln testimony whereof I aix my signature.

SVERRE QUISLING. 

